For fastest response to these software questions, it's better to open a ticket in Poser Support at: https://support.posersoftware.com

That said, there are couple of things to check:

1. Inside Poser, make sure you entered a valid username/password under Content Library|Purchases|Renderosity or PoserSoftware and that it can pull back a list of your purchases
2. If using Windows, make sure you are running Windows 10 or higher as stated in the Poser minimum system requirements (MSR) here: https://www.renderosity.com/marketplace/products/159003/poser-13-windows-and-mac Some versions of Win 7 have trouble accessing newer SSL certs and Poser will fail to authenticate.